package demo3;



abstract class Shape {

    public abstract void draw();

    /*public String name;
    public static int a;

    public void eat() {
    }*/
}

abstract class A extends Shape {
    public abstract void testA();
}

class B extends A {


    @Override
    public void draw() {

    }

    @Override
    public void testA() {

    }
}



class Cycle extends Shape {

    @Override
    public void draw() {
        System.out.println("●！");
    }
}


public class TestDemo {
    public static void main(String[] args) {
        //Shape shape = new Shape(); //编译报错，Shape是抽象类，不能被实例化
        Shape shape = new Cycle();
        shape.draw();
    }
}
